1. Field of the Invention
The present invention relates to an heat dissipation structure for light emitting diodes (LED) and, more particularly, to an LED capable of operating at the condition of high driving current, therefore delivering high intensity of light output for lighting and other applications where strong illumination of light is necessary.
2. Description of the Related Art
The light emitting diode (LED) explains by itself as the lighting device made of semiconductor p-n junction diode. Until recent years, the component has been used only as the indicators or displays of signs in instruments where intensity is not detrimental. The intensity needs only to be strong enough for human eyes to sense at short distance, such as in the applications for power On/Off indication in a TV system and similar ones, or for the digital display of numbers on clock and electronic panels. The power consumption is small and the heat dissipation is not a subject to be concerned.
However, due to the advance of LED technology nowadays, LEDs are much brighter and colorful, spreading from deep blue to beyond the visible spectrum. Hence applications of the present visible LED are greatly extended towards many new frontiers which never were expected before, such as out-door large color displays, traffic lights, automobile light signs, etc. However, even in these applications, clusters of LED lamps still have to be used to gain sufficient intensity. But the cluster structure not only needs a highly labor-intensive assembly, but also results in the packaging very space-concerned, often leading to optical design and thermal management vulnerable.
Therefore, at this moment, a high intensity LED component having a chip or an array of chips built in a compact embodiment capable of delivering high intensity of light has become paramount importance to the related industries.
It is an object of the present invention to provide a heat dissipation structure for light emitting devices, thereby it is possible that the light emitting devices having the heat dissipation structure are prevented from an increase in temperature, and suitable for an application of high intensity and high current, and reduced in size.
It is another object of the present invention to provide an package for light emitting devices, according to the structure of the package, which is allowable that the light emitted therefrom can be conformed and directed into a desired direction of light beam for specific applications, while the heat generated therefrom is easily dissipated.
According to an aspect of the invention, there is provided the heat dissipation structure for light emitting devices comprising: a metallic substrate having a top surface and a bottom surface, the top surface configured with a cup-shaped portion for the light emitting device being mounted therein and the bottom surface opposite to the top surface including a metallic solder layer deposited thereon, wherein the cup-shaped portion has an upper surface, an inner surface, and an outer surface, an electrically insulating layer deposited on the upper surface and on the outer surface, an electrically conductive electrode layer deposited on the electrically insulating layer and on the inner surface of the cup-shaped portion, and the electrically conductive electrode layer includes two divided electrodes, the one electrode formed on the inner surface of the cup-shaped portion and the other electrode formed on the upper surface and the outer surface thereof; an electrically insulating fluidic coolant filled in the cup-shaped portion; and a light transparent housing hermetically attached to the metallic substrate to seal the electrically insulating fluidic coolant filled in the cup-shaped portion, the light transparent housing having an inner surface configured with a convex portion opposite to the light emitting device.
It is preferred that the metallic substrate is made of a thermally conductive material.
It is preferred that the electrically insulating layer is made of an oxide of the thermally conductive material.
It is advantageous that the heat dissipation structure for light emitting devices further comprises a printed circuit board including the thermally conductive material, wherein the printed circuit board has a surface with at least one electrode formed thereon, and the printed circuit board is electrically connected to the metallic substrate by joining the at least one electrode to the metallic solder layer and joining the at least one electrode to the electrode formed on the upper surface and the outer surface of the cup-shaped portion.
It is preferred that the electrically conductive electrode layer is made of a light-reflective metal.
It is preferred that the light transparent housing has an outer surface configured with a convex portion opposite to the convex portion of the inner surface of the housing.